1. Field of the Invention
The present invention relates to an image forming apparatus including so-called simultaneously transferring and fixing means for primarily transferring a toner image on an image bearing member to an intermediate transferring member to transfer the toner image on the intermediate transferring member to a recording material and heating and fixing it on the recording material at the same time, and in particular, to the image forming apparatus capable of reducing the time unable to perform image formation due to a temperature change of the image bearing member.
2. Related Background Art
In recent years, an electrophotographic image forming apparatus is increasingly required to be miniaturized. Here, attention is directed, as effective means for miniaturization of the image forming apparatus, toward use of a so-called simultaneously transferring and fixing means having fixing means for fixing a toner image on a recording material integrated with secondary transferring means for transferring the toner image on an intermediate transferring member to the recording material.
As for the image forming apparatus using the simultaneously transferring and fixing means, an image bearing member receives heat from an intermediate transferring belt heated on fixing simultaneous with transfer during image formation so that temperature of the image bearing member changes. And there is a possibility that characteristics of the image bearing member change due to the change in temperature of the image bearing member so as not to form a good electrostatic image.
For that reason, means for detecting the temperature of the image bearing member is provided, and electrostatic image formation to the image bearing member is not performed in the case where the temperature of the image bearing member is out of a range of temperature capable of forming the electrostatic image. And if the temperature of the image bearing member gets into the range of temperature capable of forming the electrostatic image, the electrostatic image formation to the image bearing member is started.
However, there arose a problem that productivity of the image forming apparatus is reduced because the image formation is not performed until the temperature of the image bearing member gets into the range of temperature capable of forming the electrostatic image.